1. Field of the Invention
The present invention relates to a cable harness to be used for an opening and closing part, a twisting part, or a U-shaped sliding part of equipment.
2. Prior Art
In recent years, in accordance with widespread of laptop computers, mobile phones, compact video cameras or the like, high-speed data transmission and high data density for these device are required in addition to the downsizing and down-weight of these devices. Further, in these devices, displays are configured to be openable and closable, twistable, or slidable. For that reason, a cable harness in which uitrafine coaxial cables are bundled together has been used as a harness between a main body and a display of the device.
The cable harness is wired while contacting a chassis in a narrow space between the display and the main body. Therefore, the middle of the harness is bundled and fixed by a tape made of PTFE (polytetrafluoroethylene) to prevent the coaxial cables from being pinched or abrasion.
FIG. 10 shows a conventional cable harness 121. In a middle part of the cable harness 121 (part except terminals), an electric wire 122 is wrapped and bundled by a tape 123 made of PTFE in order to prevent the electric wire 122 from being pinched or abrasion. A connector 124 is installed to both terminals of the electric wire 122. The connector 124 has plural poles, and plural wires 125 inside the electric wire 122 are connected to the poles of the connector 124, respectively. The terminals of the tape 123 are wrapped by an adhesive tape 126.
As to jacket material for an electric wire to be used for opening and closing part, twisting part, or U-shape sliding part (hereinafter referred to as “movable part”) of the equipment such as mobile phones, fluorine resin has been mostly used. Herein, the “U-shape sliding” means a sliding operation along a U-shaped frame provided for connecting an upper casing and a lower casing configured to partially surround the upper casing, for example, an upper casing for mounting a liquid crystal display and a lower casing as a main body in a mobile phone. As to a binder tape material, PTFE which is a fluorine resin based material has been mostly used. However, the fluorine resin is apt to generate static electricity. Further, electromagnetic interference (EMI) between circuits may be caused by electromagnetic wave radiated from a signal line or an antenna in vicinity thereof. Therefore, it is necessary to suppress electrostatic noise caused by friction between the jackets of the electric wires or between the PTFE tapes at the movable part as well as the electromagnetic wave radiated from the signal line.
However, the entire cable harness bundled in one direction by the PTFE tape is lacking in flexibility and balance. Therefore, this type of the cable harness is apt to be oriented in a warping direction and to be repulsive, when the cable harness is installed in the equipment.
Further, movement of coaxial cables included in the cable harness is restricted by the PTFE tape, so that proper mechanical characteristics of the coaxial cables may be degraded easily.
Still further, the cable harness bundled by the PTFE tape is apt to be bent in a round shape. Therefore, it is difficult to install this type of the cable harness in a space of a casing with irregular configuration such as oval shape, rectangular shape, or triangular shape. If this type of the cable harness is forced to be installed in the space of the casing with the irregular configuration, the electric wire may be damaged by pressing.
Recently, the use of the cable harness in a slide-type mobile phone has been studied. However, operation of U-shape sliding cannot be performed smoothly, if the cable harness is bundled by the PTFE tape.
To solve these disadvantages, Japanese Patent Laid-Open No. 2006-24372 (JP-A 2006-24372) proposes following configuration. In a cable harness disclosed by JP-A 2006-24372, a braid sleeve is formed by using tinsel-copper, and a wire group is inserted through the braid sleeve. Then, the tinsel-copper may be connected to a ground potential part of an electric connector. The tinsel-copper may be connected to a ground terminal separately to be connected to a ground terminal in the equipment. The tinsel-copper may be connected to an outer conductor of a coaxial cable at a middle part of the wire group.
However, in the cable harness disclosed by JP-A 2006-24372, the tinsel-copper is so hard that the wire group should be inserted into a sleeve after being protected and bundled by an insulating tape, in order to prevent the copper foil from grazing and damaging a wire jacket due to direct contact between the wire group and the sleeve at a bending part. Such a configuration gives a factor of raising the production cost. Also, because the wire group is bundled by the insulating tape, the U-shape sliding cannot be performed smoothly, similarly to the cable harness bundled by the PTFE tape mentioned above. Also, the tinsel-copper is made by wrapping a copper foil tape on a high tension fiber. Therefore, the copper foil may be deteriorated or fall off on the substrate due to frequent flexion movement, thereby causing failure such as short-circuit.